Potential impact of DSM-5 criteria on autism spectrum disorder prevalence estimates

Abstract

Importance: The DSM-5 contains revised diagnostic criteria for autism spectrum disorder (ASD) from the DSM-IV-TR. Potential impacts of the new criteria on ASD prevalence are unclear.

Objective: To assess potential effects of the DSM-5 ASD criteria on ASD prevalence estimation by retrospectively applying the new criteria to population-based surveillance data collected for previous ASD prevalence estimation.

Design, setting, and participants: Cross-sectional, population-based ASD surveillance based on clinician review of coded behaviors documented in children's medical and educational evaluations from 14 geographically defined areas in the United States participating in the Autism and Developmental Disabilities Monitoring (ADDM) Network in 2006 and 2008. This study included 8-year-old children living in ADDM Network study areas in 2006 or 2008, including 644 883 children under surveillance, of whom 6577 met surveillance ASD case status based on the DSM-IV-TR.

Main outcomes and measures: Proportion of children meeting ADDM Network ASD criteria based on the DSM-IV-TR who also met DSM-5 criteria; overall prevalence of ASD using DSM-5 criteria.

Results: Among the 6577 children classified by the ADDM Network as having ASD based on the DSM-IV-TR, 5339 (81.2%) met DSM-5 ASD criteria. This percentage was similar for boys and girls but higher for those with than without intellectual disability (86.6% and 72.5%, respectively; P < .001). A total of 304 children met DSM-5 ASD criteria but not current ADDM Network ASD case status. Based on these findings, ASD prevalence per 1000 for 2008 would have been 10.0 (95% CI, 9.6-10.3) using DSM-5 criteria compared with the reported prevalence based on DSM-IV-TR criteria of 11.3 (95% CI, 11.0-11.7).

Conclusions and relevance: Autism spectrum disorder prevalence estimates will likely be lower under DSM-5 than under DSM-IV-TR diagnostic criteria, although this effect could be tempered by future adaptation of diagnostic practices and documentation of behaviors to fit the new criteria.

Figure 1. Children Who Met DSM-5 Autism Spectrum Disorder (ASD) Criteria

The bar graph shows the proportion of children who met DSM-5 ASD criteria among Autism and Developmental Disabilities Monitoring (ADDM) Network ASD case children (N = 6577). Data are stratified by the number of DSM-IV-TR ASD criteria for surveillance years 2006 and 2008. Percentages denote those who met DSM-5 criteria among children with a given number of DSM-IV-TR criteria.

Figure 2. Comparison of Prevalence Estimates

The graph shows a comparison of previously reported Autism and Developmental Disabilities Monitoring (ADDM) Network autism spectrum disorder (ASD) prevalence estimates (2000–2008 surveillance years) to prevalence using DSM-5 ASD criteria (2006–2008 surveillance years). The population size (or geographic area) for some ADDM Network sites varied from year to year. The data collection methods for the 2002 and 2004 surveillance years are not compatible with the application of DSM-5 criteria. The line with diamonds indicates previously reported ADDM Network ASD prevalence estimates based on DSM-IV-TR criteria. The line with circles shows the prevalence of children meeting DSM-5 ASD criteria. The shaded area shows the prevalence of children who are not currently meeting ADDM Network ASD case status but may meet ASD case status using DSM-5 criteria. The error bars indicate 95% CIs.